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H.K.D.H. Bhadeshia,
Phase Transformations Group,
Department of Materials Science and Metallurgy,
University of Cambridge,
Cambridge, U.K.
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To calculate the differential (w.r.t. X) of the natural logarithm of the
activity of carbon in austenite.
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Language:  FORTRAN

Product form:  Source code 
DOUBLE PRECISION FUNCTION MAP_STEEL_DCG(X, T, W, R)
DOUBLE PRECISION X, T, W, R
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MAP_STEEL_DCG gives the differential (with respect to X, the carbon concentration in
austenite in mole fraction) of the natural logarithm of the activity of carbon in
austenite [1,2,3].
The carboncarbon interaction energy used is calculated according to [4].
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 J.R. Lacher, Proc. Camb. Phil. Soc. Math. Phys. Sci.,
33, (1937), 518.
 R.H. Fowler and E.A. Guggenheim, Statistical Thermodynamics,
Cambridge University Press, New York, (1939).
 G.J. Shiflet, J.R. Bradley, and H.I. Aaronson, Metall. Trans A,
(1978), 9991008.
 H.K.D.H. Bhadeshia, Metal Science, 14, (1980), 230232.
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Input parameters
 X  real
 X is the carbon concentration in austenite x^{gamma} (in mole fraction).
 T  real
 T is the absolute temperature (in kelvin).
 W  real
 W is the carboncarbon interaction energy in austensite w (in joules per mole, Jmol^{1}).
 R  real
 R is the universal gas constant (in joules per mole per kelvin, Jmol^{1}K^{1}).
Output parameters
 MAP_STEEL_DCG  real
 MAP_STEEL_DCG is the differential (w.r.t. X) of the natural logarithm of the activity of carbon in austenite.
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None.
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See references [3,4].
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None.
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1. Program text
DOUBLE PRECISION X,T,W,R,MAP_STEEL_DCG,XDCG
INCLUDE 'map_constants_gas.f'
READ (5,*) X,T,W
XDCG = MAP_STEEL_DCG(X,T,W,R)
WRITE (6,10) XDCG
10 FORMAT ('XDCG = ',D13.5)
STOP
END
2. Program data
0.11871D01 931.0 8352.3
3. Program results
XDCG = 0.94596D+02
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None.
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activity of carbon, austenite
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Download source code
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